Although there has been much research documenting the limbic system as the substrate for emotion, there is also new evidence indicating a special role for the neocortex in emotional processing. The main purpose of the current project is to test current notions regarding the neuropsychology of neocortically-processed emotion within five domains: hemisphere specialization, emotional valence, processing mode, expression type, and communication channel. Hypotheses regarding interhemispheric specialization and valence will be tested: (a) right hemisphere dominance for emotion, regardless of valence; (b) right hemisphere dominance for negative emotions and left hemisphere dominance for positive emotions; and (c) right hemisphere dominance for the perception of emotions of both valences and differential dominance for expression as a function of valence. Intrahemispheric specialization as a function of processing mode also will be addressed to determine whether perception is independent from expression of emotion, with "anterior" cortical regions associated with expression and "posterior" regions with perception. To learn more about the neural systems underlying expressive behavior, both posed and spontaneous expressions will be elicited. Finally, three channels of communication (facial, prosodic, lexical) will be examined to evaluate the extent to which there is a unitary system underlying emotional processing. Subjects will be 48 right brain-damaged, 48 left brain-damaged, and 48 normal control right-handed males and females. Brain-damaged patients with anterior or posterior cortical lesions will be included. For perception, subjects will identify photographs of facial expressions, recordings of intoned sentences, and written stimuli conveying feelings. For expression, subjects will be videotaped, audiotaped, and transcribed while posing, reliving emotional experiences, and responding to emotionally-laden slides. Nonemotional tasks will also be administered to control for cognitive, perceptual, and motoric factors that might confound performance on tasks of emotional processing. An important end-product of this project will be an extensive battery of quantitative measures for the objective assessment of emotion in brain- damaged populations.